Conventionally, an air conditioner for a vehicle is described in Patent Document 1 (JP 3538845 B2 corresponding to U.S. Pat. No. 5,299,431). The air conditioner includes a heating heat exchanger and a cooling heat exchanger to heat or cool air blown into a vehicle compartment. A refrigerant cycle of the air conditioner can be switched between a heating circuit, in which the heating heat exchanger is arranged, and a cooling circuit, in which the cooling heat exchanger is arranged. The air conditioner further includes an electromagnetic valve to switch the refrigerant cycle between the heating circuit and the cooling circuit.
In the air conditioner of Patent Document 1, the refrigerant cycle may be different between before and after a defrosting operation, in which air is blown to a windshield of the vehicle, is performed. When the cooling circuit is changed to the heating circuit, water adhering to a surface of the cooling heat exchanger may evaporate. Therefore, fogging of the windshield and bad odor generation may occur.